This developmental application (R34) requests funds to refine and pilot test a flexible Partner notification services Pre-exposure Prophylaxis (PS-PrEP) intervention that will engage existing department of public health (DPH) partner notification services in linkage to clinical PrEP care for at risk HIV seronegative persons from diverse backgrounds. These funds are requested because there remains a stark efficacy implementation divide following randomized controlled trials which have demonstrated partial PrEP efficacy. Following these trials, DPHs have yet to integrate PrEP into existing HIV prevention programs resulting in few people on PrEP and those who might benefit most (highest risk populations) are not receiving it. To address these gaps, we aim to integrate PrEP into existing DPH activities, and in particular, DPH partner notification services. DPH partner notification services implemented by Disease Intervention Specialists (DIS) are widespread in high HIV prevalence areas domestically and have great potential. Partner notification services (engaging the risk partners of newly infected HIV persons), is recommended by the CDC for HIV prevention and is frequently conducted by public health departments. In data from South Chicago over 50% of these risk contacts are HIV infected. This high HIV prevalence outpaces that of traditional risk groups in the same geographic area and suggests that we shift our thinking of who an appropriate candidate for PrEP linkage is from individual risk (anal sex, injecting drugs), to network risk (people connected to HIV infected persons). PS-PrEP tests the integration of PrEP into routine DPH services by training DIS staff to provide brief tailored PrEP linkage planning/motivation, mini-booster sessions via text/phone, and to directly link clients int PrEP care. PS-PrEP will set the stage for a large trial by examining two key components of early PrEP care: 1) efficacy of PS-PrEP in linking high-risk seronegative clients to PrEP care as part of partner notification services; and 2) how personal characteristics (e.g. risk behavior) and downstream PrEP cascade metrics (e.g. retention and adherence to PrEP) of study participants identified through partner notification services compare to other individuals initiating PrEP withi the same clinical context and time frame. We aim to: 1) Refine the PS-PrEP intervention protocol, materials and assessments by shifting more of the intervention to focus on direct PrEP linkage and by developing a network visualization component where participants complete an interactive sociogram of individuals in their own risk network; 2) Pilot test the feasibility (reac, adoption, safety and implementation) and initial efficacy (higher linkage to care) of the PS-PrEP intervention versus treatment as usual at 3 months post randomization among a sample of contacts >18 years old recruited from partner notification services; and 3) Compare sociodemographic, HIV risk and two distal PrEP cascade metrics (retention and adherence) of PS-PrEP intervention participants linked to PrEP care with other individuals initiating PrEP within the same clinical context and time frame (12 months).